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thinking about getting solar panals

  • 21-01-2009 4:05am
    #1
    Registered Users Posts: 206 ✭✭


    Thinking about getting solar panals installed on my house in the next few months,
    can anyone tell me is it really worht it will i really reduce my electricity bill?
    Does anyone know on average how much would it cost for 2 big solar panals and to get it all installed?
    I was told that you get a grant from the government for using solar panals? is this true and also how much do you get?
    thanks :)


«1

Comments

  • Registered Users Posts: 3,699 ✭✭✭bamboozle


    prepare for a lot of differing replys!
    the amount of panels depends on your ultimate requirements..how many people, use for heating or hot water only, is house a new build..is it south facing..
    for what its worth i mentioned below i am purchasing through a cork based company who seem to be extremely cheap in comparison to other companies and i have not heard anything bad about them, if you want name pm me!


  • Closed Accounts Posts: 188 ✭✭MickLimk


    Have a look on here as a place to start.

    http://www.sei.ie/Grants/GreenerHomes/

    Bamboozle is right, you're likely to get a lot of different replies!

    There are those out there who offer one or two options but a proper system is tailored to suit the building, it's existing heating system, it's occupants and their habits. I'd put it this way, if I want to get a decent sized car, how much is it going to cost me?! A lot of questions there that need to be answered...

    Regardless of where you eventually source the equipment, buy it yourself or just employ someone to supply and install the lot, to be eligible for the SEI grant, the equipment must be installed and commissioned by a registered SEI installer.

    Bamboozle, just in case you weren't aware, that company you mention has a depot in Dublin which may be a lot easier than travelling to west Cork!


  • Registered Users Posts: 3,699 ✭✭✭bamboozle


    thanks Mick, have you expernience with the company?


  • Closed Accounts Posts: 188 ✭✭MickLimk


    bamboozle wrote: »
    thanks Mick, have you expernience with the company?

    Experience with the company's products, yes. Association with the company, no!


  • Registered Users Posts: 3,699 ✭✭✭bamboozle


    MickLimk wrote: »
    Experience with the company's products, yes. Association with the company, no!


    care to expand on that? would u recommend their product?


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  • Closed Accounts Posts: 188 ✭✭MickLimk


    Assuming we're talking about the same company that are the sole Irish distributors for a UK company (N......n), then I've no problem recommending their products amongst others I've used.

    Their tubes are of Chinese origin but they've built up a very good cost/performance reputation in the UK over a good number of years, so much so that other companies are now offering counterfeit versions of their products!

    I actually have some of those tubes at the moment waiting for suitable time for the customer. PM me if you have any other questions.


  • Registered Users Posts: 3,699 ✭✭✭bamboozle


    yes thats the company, thanks for that,


  • Closed Accounts Posts: 109 ✭✭pool fan


    Can you pm me the company name,im getting a few prices now.


  • Registered Users Posts: 111 ✭✭BMurr


    MickLimk wrote: »

    Regardless of where you eventually source the equipment, buy it yourself or just employ someone to supply and install the lot, to be eligible for the SEI grant, the equipment must be installed and commissioned by a registered SEI installer.

    Are you sure, I thought that you could install it yourself but that to get the grant you had to have it commissioned by a registered SEI bod?


  • Closed Accounts Posts: 188 ✭✭MickLimk


    BMurr wrote: »
    Are you sure, I thought that you could install it yourself but that to get the grant you had to have it commissioned by a registered SEI bod?

    From the SEI website:

    Qualification Criteria
    • The following conditions will apply in the evaluation of grant applications and all conditions must be met in advance of any approval of a grant.
    • Applicant must confirm that the dwelling for which they are applying is an existing dwelling, has an existing heating system and has been occupied for a minimum of one year.
    • Applicant must be the homeowner and must have full possession of the property where the system is to be installed.
    • Applicant must fully complete the Greener Homes Application Form with information valid at time of application.
    • Applicant must supply bank account and sort code details to facilitate electronic payment of the grant. (Please note that currently we cannot process EBS and Credit Union accounts).
    • Applicant must agree to be bound by the Terms and Conditions of the Scheme (see Section 11 of the Application Guide)
    • Product must be listed, at the date of application, on the Registered Product List (available on request or online at www.sei.ie/greenerhomes )
    • Installer must be listed, at the date of application and on the date of system commissioning, on the Registered Installer List
    • SEI must still have adequate funding available to it pursuant to the relevant phase of the Scheme in order to be able to approve the relevant application

    I'd say if you want a definitive answer on it, try and call them on 1850 734 734 or email greenerhomes@sei.ie

    When applying for the grant, you do need an installers name and registered ID number. I still think though that there is a bit of a grey area as the commissioning report has space for a separate installer and commissioner with the installers registered ID only needing to be filled in if available.

    That's not to say that there aren't plenty of self installs out there that registered 'Installers' have signed off on! The problem for the 'Installer' in these cases is when the SEI decide to inspect a system (and I do know of systems that were inspected). If there are problems, then the 'Installer' who signed of on the commissioning is liable for any problems with the system and in the worst case could be struck off the registered list.

    Obviously as an installer, I have a vested interest in this so that's just my 2c. The flip side to that is that suppliers generally make more money selling direct to the public instead of installers as they don't have to give them trade prices so take that into account too!


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  • Registered Users Posts: 111 ✭✭BMurr


    Cheers for that Mick. Your last point about prices available to installers versus those available to DIY bods is a good one and well worth considering .


  • Registered Users Posts: 2,009 ✭✭✭blindsider


    MickLimk wrote: »
    Assuming we're talking about the same company that are the sole Irish distributors for a UK company (N......n), then I've no problem recommending their products amongst others I've used.

    Their tubes are of Chinese origin but they've built up a very good cost/performance reputation in the UK over a good number of years, so much so that other companies are now offering counterfeit versions of their products!

    I actually have some of those tubes at the moment waiting for suitable time for the customer. PM me if you have any other questions.

    Hi Folks - any chance of a PM with their details? I'm based in Cork, and they sound like a good option - thanks!


  • Closed Accounts Posts: 12 fordes


    hi all,

    I am currently building a house in the cork area and i am looking to install solar tubes. I was wondering if people could please pm me with details of companies that ye have used and were very happy with. I am looking to the entire system including the hot water tank, which is preferable glass lined or stainless steel.

    Thanks


  • Closed Accounts Posts: 188 ✭✭MickLimk


    PM's sent...


  • Registered Users Posts: 48 rosnacanee


    if someone could pm me the above details aswell it would be great thanks a million


  • Registered Users Posts: 109 ✭✭littlecbear


    Could you send me the supplier name too please?
    thanks


  • Closed Accounts Posts: 188 ✭✭MickLimk


    PM's sent.


  • Registered Users Posts: 1,724 ✭✭✭BoozyBabe


    Hope ye don't mind me jumping in here.
    I've been considering for a while now, & then I rule it out, come back to it a few months later, rule it out again & where I'm at now is that I'm almost certain I'm not installing it.
    But, just before I put it to bed for the very last time, I think it'd be worth putting it up here to hear your views on it.

    I've decided to install an air to water heat pump, which will be running all the time anyway, with a constant supply of hot water, so why would I install solar?
    You say, because in the summer time you'd have the heating off & have no way to heat water.
    But, my thoughts on that is it'd take an awful lot of immersion heated baths or showers before the solar would begin to pay for itself!

    Which leads to an obvious question, which is something I'm not sure about. How much hot water DOES two adults need in a day? A couple of showers... What else? Do dishwashers take in hot water, or do they heat up cold intake water anyway? Can't washing machines also work of cold water, plus aren't both of these pieces of equipment becoming more & more energy conscious in that they produce the same cleaning results now at much lower wash temperatures..
    What else is there?

    If it's really only for the morning shower, then 'i really can't see how solar will benefit us that much.

    What's your take on this? Don't be afraid to contradict me. I'd rather be proved wrong at this stage when all is still on paper instead of having to retrofit afterwards due to an oversight.

    Thanks,
    BB


  • Registered Users Posts: 109 ✭✭littlecbear


    MickLimk wrote: »
    PM's sent.

    THANKS A MIL FOR THAT INFO


  • Closed Accounts Posts: 4 namara


    I've got a couple of prices recently for panels & new cylinder as part of a refurb and been quoted for 'direct flow' and 'heat pipe' alternatives with a vacuum tube system. Anyone have any experience of either/both of these options?


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  • Closed Accounts Posts: 188 ✭✭MickLimk


    In a heat pipe system, there is no transfer of liquid between the tube and the rest of the solar thermal system. The water/antifreeze mix circulates through the the system (cylinder coil/pump/pipework) and through the solar manifold on the roof. The heat pipes fit into sealed pockets in the manifold to transfer heat from the evacuated tubes to the water/antifreeze mix and onto the hot water cylinder. This is often known as a 'dry' connection.

    In the direct flow systems, the water/antifreeze mix flows to the manifold where each tube is individually connected to two separate pipes, a flow and a return. The water/antifreeze mix flows down through a U pipe in each tube, heating as it's going, back up to the manifold and continues on to the cylinder. Call this a wet connection.

    To me, the dry connection (heat pipe) system has a number of advantages over the wet connection (direct flow/U pipe):
    1. More reliable as there are less connections to fail. In an example of a 20-tube panel, the dry system has only 2 plumbing connections to make (and potentially leak), 1 in and 1 out. On a 20 tube wet system, there are 42 connections, 1 in and 1 out plus 2 connections per tube. Each connection is a potential weak point or source of leakage.
    2. Easier to install: With a dry system, the manifold and frame are usually assembled on the ground, installed on the roof, filled and pressure tested before any tubes are added. This makes it easier to manage on a roof and also safer to work on in my opinion. There's also the added benefit of being able to work on this type of system on the hottest days without having to worry about getting burnt or the system overheating before the installation is complete. The panels for the direct system are usually supplied pre-assembled making them more like flat plates when it comes to installation.
    3. More robust: There is always a possibility of damage. If a wet system is damaged and a single U pipe fractured, then the water/antifreeze mix will leak out and the system will not work at all until fully repaired. If it is left in this state for a period of time, there is a chance that more damage could be done by repeated overheating of the panel due to the lack of any fluid in the manifold. As the dry system has no direct connection with the water/antifreeze mix, breaking a heat pipe tube should not cause the system to leak and drain itself onto your roof. The system will continue to operate but just lacking the input from that broken tube.
    4. Easier to maintain and repair: To replace a single damaged tube on a dry system is a quick and simple job. Remove offending tube from manifold, replace with new one. With the direct system, the entire system must be drained down (if it hasn't already leaked), the tube disconnected from the flow and return pipes in the manifold, new tube connected and entire system flushed, vented and repressurised.
    Of course there has to be an advantage of a direct system and that is often performance. Depending on the brands of direct and heat pipe, direct systems may give a slightly higher performance and quicker reaction time to short spells of sunshine.

    There is also the possibility that you are talking about an indirect vs. direct system but I'm not going there at the moment other than to say avoid a direct system!


  • Closed Accounts Posts: 4 namara


    Thanks for the comprehensive reply! The main advantage for the heat pipe emphasised in the marketing material was a temperature limiting feature that apparently doesn't apply to the direct flow system. The points in your reply sound more compelling reasons to favour the HP option!


  • Registered Users Posts: 1,627 ✭✭✭quentingargan


    namara wrote: »
    Thanks for the comprehensive reply! The main advantage for the heat pipe emphasised in the marketing material was a temperature limiting feature that apparently doesn't apply to the direct flow system. The points in your reply sound more compelling reasons to favour the HP option!
    Ah, you're looking at a heat pipe system that has the heatpipe welded into the glass tube. These are quite an expensive tube to replace when they fail (which they all will after 20 years) so be aware of this. There are other heat pipe systems that have a flask - this is a lot cheaper to replace in the event of damages etc.

    I prefer to use a heat dump to get rid of the surplus heat. The system you are using leaves the heat locked into the flask which can get to very high temperatures, albeit that those temperatures are kept away from the wet system...

    Another problem with direct flow is that you have to be careful that the panels are a good bit higher than the cylinder and expansion vessel. I have seen them thermo-driving, building up steam which pushes water around the system so that they boil again, filling the expansion vessel. I'm not sure yet if plumbers fully understand 'em.


  • Closed Accounts Posts: 4 namara


    Thanks for the reply. I thought that choosing the solar panel setup was going to be one of the simplest parts of the refurb but it looks like I have a bit more work to do to figure out what route to go!


  • Closed Accounts Posts: 2,948 ✭✭✭gizmo555


    BoozyBabe wrote: »
    But, my thoughts on that is it'd take an awful lot of immersion heated baths or showers before the solar would begin to pay for itself!

    I checked this myself before ruling out a solar hot water installation and came up with a back of the envelope calculation that compared with heating water by electricity, in my family of 2 adults & 3 young children, it would take about 25 years for a solar system to pay for itself (and this is after allowing for the SEI grant). Compared with hot water from a wood pellet boiler, payback was more like 35 to 40 years - and this on a system with a design life of 20 years.

    My calculations are confirmed by this article on the Sustainability Ireland website: http://www.sustainability.ie/solararticle.pdf

    In Ireland it currently costs €5-8000 to have a domestic solar heating system installed. This seems extraordinarily bad value for money. At current oil prices and typically boiler efficiencies, it will cost under €400 per annum to provide domestic hot water for a family of four. Of this, the solar fraction (the proportion of total hot water provided by the solar heating system) may be as
    little as 15-20%. In such cases, the value of the solar hot water may be no more than €60 per annum. A detailed assessment of solar water heating by Seamus Hoyne on behalf of the Tipperary Institute estimated the payback on a solar thermal system as 40 years! (see www.ilsu.ie/documents/SemRE/SHSolar.pdf)


    I know there are environmental reasons for considering solar hot water, but there are other renewable energy sources, such as wood, and from an economic standpoint, solar hot water makes no sense at all. You should make sure that you have looked at every other way of improving your home's energy efficiency before putting money into a solar system.


  • Registered Users Posts: 1,627 ✭✭✭quentingargan


    gizmo555 wrote: »
    I checked this myself before ruling out a solar hot water installation and came up with a back of the envelope calculation that compared with heating water by electricity, in my family of 2 adults & 3 young children, it would take about 25 years for a solar system to pay for itself (and this is after allowing for the SEI grant). Compared with hot water from a wood pellet boiler, payback was more like 35 to 40 years - and this on a system with a design life of 20 years.

    My calculations are confirmed by this article on the Sustainability Ireland website: http://www.sustainability.ie/solararticle.pdf

    In Ireland it currently costs €5-8000 to have a domestic solar heating system installed. This seems extraordinarily bad value for money. At current oil prices and typically boiler efficiencies, it will cost under €400 per annum to provide domestic hot water for a family of four. Of this, the solar fraction (the proportion of total hot water provided by the solar heating system) may be as
    little as 15-20%. In such cases, the value of the solar hot water may be no more than €60 per annum. A detailed assessment of solar water heating by Seamus Hoyne on behalf of the Tipperary Institute estimated the payback on a solar thermal system as 40 years! (see www.ilsu.ie/documents/SemRE/SHSolar.pdf)

    I know there are environmental reasons for considering solar hot water, but there are other renewable energy sources, such as wood, and from an economic standpoint, solar hot water makes no sense at all. You should make sure that you have looked at every other way of improving your home's energy efficiency before putting money into a solar system.

    I'm afraid that magazine, in some respects, has more manure than a herd of frightened bullocks on fresh pasture. If you pay €8K for a system, you'd better hope it will supply more than 15% of your hot water.

    labour costs are on the way down, and I reckon you should be able to get a modest system installed for about €4K, a large one for more than that. Unless you have dormers or some other complication, the prices will soon come down to those levels. Cylinders, panels and labour are all falling in price in the current market, and while that is bad news for some, it is good news for others.

    Your system will be displacing your most expensive hot water. In the winter time, your central heating heats the water on its way to the radiator at a cost of between 4c and 7c per KwHr depending on boiler efficiency. During the summer, when the heating is off, your hot water is probalby costing you twice that. So although your solar fraction is about 60%, this is displacing virtually all of your more expensive summer fraction. I reckon the savings are about €300 to €350 a year for most houses.

    I agree many installers over-egged it claiming payback times of 5 years - that was always ridiculous. But a ten year payback time after the grant is like the bank giving you 10% on deposit. That'd be a no-brainer. Go for it, but shop around....


  • Closed Accounts Posts: 2,948 ✭✭✭gizmo555


    labour costs are on the way down, and I reckon you should be able to get a modest system installed for about €4K

    You could also buy an awful lot of insulation for four grand and the cheapest, most environmentally friendly energy is the energy you don't use as a result of having proper insulation. I stand by my opinion that unless one has an unlimited budget, a solar hot water system is the very last thing to go on the energy efficiency shopping list. I take the point you made in another thread that its easier to justify in a new build, when some system has to go in anyway and you're only looking at the marginal cost of adding the solar components. On the other hand, there's no grant for that . . . .
    Your system will be displacing your most expensive hot water. In the winter time, your central heating heats the water on its way to the radiator at a cost of between 4c and 7c per KwHr depending on boiler efficiency. During the summer, when the heating is off, your hot water is probalby costing you twice that. So although your solar fraction is about 60%, this is displacing virtually all of your more expensive summer fraction. I reckon the savings are about €300 to €350 a year for most houses.

    Can you clarify your assumptions for annual domestic hot water energy use and calculations for solar energy savings? This Canadian Greenpeace website, using figures it says are originally sourced from the OECD reckons that on average, domestic hot water uses 3,200 kWh annually using electricity, or 3,800 kWh using oil. I don't imagine we use substantially more or less hot water than the Canadians, but I could be wrong . . .

    http://www.greenpeace.org/international/campaigns/climate-change/take_action/your-energy

    It would cost about €600 p.a. for 3,200 kWh of standard tariff electricity or about €315 if using night rate electricity. (If you used night rate, you could also save money by running appliances like washing machines, dishwashers and tumble dryers at night.) If I use your assumptions above to guesstimate an average cost per kWh of 10.5c for oil, the 3,800 kWh would cost about €400. I find it very hard to believe one could make savings anywhere near €350 on those sorts of costs.


  • Closed Accounts Posts: 2,389 ✭✭✭Carlow52


    A point which seems to be made a number of times in this thread thus far is that 4k on a Solar thermal HW set up would be better spent on insulation.

    How does better insulation deliver cheaper hot water?

    In terms of the payback argument, at USD 40 a barrel the the payback is long, but at 147 or 200 a barrel the payback is much better. The other point is that if oil is at 147, the cost of panels will go up so it is best do it now.

    Solar hot water can also be used to feed the washing machine and dishwasher


  • Registered Users Posts: 14,905 ✭✭✭✭CJhaughey


    Carlow52 wrote: »

    Solar hot water can also be used to feed the washing machine and dishwasher

    This is a point that most are not factoring in the calculation I believe.
    AFAIK all dishwashers now are cold feed only and have internal heating elements to heat the water to whatever temp is required, feeding a dishwasher warm water should make a lot of difference to the energy requirements of that appliance.
    The same goes for washing machines, most if not all have cold feed only now.
    They cite the fact that it is more efficient to heat the water in the machine rather then using a boiler to heat the water, this takes no account of the possibility of using Solar heated water to do the same job.
    When we built we ordered an Admiral Toploader machine machine as it had hot and cold feeds and being right next to the 400l tank it made perfect sense to use SHW.


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  • Closed Accounts Posts: 2,948 ✭✭✭gizmo555


    Carlow52 wrote: »
    A point which seems to be made a number of times in this thread thus far is that 4k on a Solar thermal HW set up would be better spent on insulation.

    Having reviewed the thread I find it was actually made only once, by me.
    Carlow52 wrote: »
    How does better insulation deliver cheaper hot water?

    The OP asked for views on whether solar hot water is a cost effective investment for retrofitting in an existing house. I gave my opinion that this is at best doubtful and from figures given in other posts, reasonable payback periods seem to rely on assuming very costly alternatives for heating water. I didn't say don't install solar hot water. I do say that it is likely to be one of the least cost effective energy efficiency measures one could take and if, for example, one doesn't already have enough insulation (very likely in most Irish houses) this will deliver a much greater bang for your buck.
    Carlow52 wrote: »
    In terms of the payback argument, at USD 40 a barrel the the payback is long, but at 147 or 200 a barrel the payback is much better. The other point is that if oil is at 147, the cost of panels will go up so it is best do it now.

    The same applies to other energy efficiency measures, and if their payback periods are shorter than solar hot water now, they will remain shorter than solar as energy prices rise. For example, a modern condensing oil boiler could knock in the order of 15% off one's oil bill. This would provide comparable annual savings to best case solar HW savings for around half the cost. Some of these types of boiler are also designed to efficiently spot heat water on demand, which I imagine would knock a serious hole in Quentin's assumptions about the likely cost of heating water using oil in summertime.
    Carlow52 wrote: »
    Solar hot water can also be used to feed the washing machine and dishwasher

    As CJHaughey has pointed out, in general it can't. Yet every analysis I've seen of energy savings from solar hot water assumes it can. This would cause me even greater doubt as to the likely real life payback period for solar HW.


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